To better query regional sources of metal(loid) exposure in an under-communicated region, available scientific literature from 50 national universities (undergraduate and graduate theses and dissertations), peer-reviewed journals, and reports published in Spanish and English were synthesized with a focus on metal(loid) bioaccumulation in Peruvian food and medicinal products utilized locally. The study considered 16 metal(loid)s that are known to exert toxic impacts on humans (Hg, Al, Sb, As, Ba, Be, Cd, Cr, Sn, Ni, Ag, Pb, Se, Tl, Ti, and U). A total of 1907 individual analyses contained within 231 scientific publications largely conducted by Peruvian universities were analyzed. These analyses encompassed 239 reported species classified into five main food/medicinal groups—plants, fish, macroinvertebrates and mollusks, mammals, and “others” category. Our benchmark for comparison was the World Health Organization (Codex Alimentarius) standards. The organisms most frequently investigated included plants such as asparagus, corn, cacao, and rice; fish varieties like trout, tuna, and catfish; macroinvertebrates and mollusks including crab and shrimp; mammals such as alpaca, cow, chicken eggs, and milk; and other categories represented by propolis, honey, lichen, and edible frog. Bioaccumulation-related research increased from 2 to more than 25 publications per year between 2006 and 2022. The results indicate that Peruvian food and natural medicinal products can have dangerous levels of metal(loid)s, which can cause health problems for consumers. Many common and uncommon food/medicinal products and harmful metals identified in this analysis are not regulated on the WHO’s advisory lists, suggesting the urgent need for stronger regulations to ensure public safety. In general, Cd and Pb are the metals that violated WHO standards the most, although commonly non-WHO regulated metals such as Hg, Al, As, Cr, and Ni are also a concern. Metal concentrations found in Peru are on many occasions much higher than what has been reported elsewhere. We conclude that determining the safety of food/medicinal products is challenging due to varying metal concentrations that are influenced not only by metal type but also geographical location. Given the scarcity of research findings in many regions of Peru, urgent attention is required to address this critical knowledge gap and implement effective regulatory measures to protect public health.

Climate change and increases in human activities are threatening water availability in the Arequipa Region (southern Peru). However, to date, there has not been a comprehensive inventory of surface water data or an investigation of current surface water conditions or forecasted future conditions resulting from increased anthropic demand or stresses from climate change. This study evaluates surface water resources management including storage, diversions, and conveyance in the Arequipa Region, while creating a tool for the evaluation of future scenarios in the five main watersheds of this arid region of southern Peru. State-of-the art, open-source modeling software was used. Water uses for each watershed were evaluated against predicted reservoir inflows and streamflows for different periods. In addition to the above, 12 climate change models and different shared socioeconomic pathways (SSP) were ensembled for the five watersheds. A semi-distributed approach and an innovative simulation splitting approach was used for each watershed, which allowed for different starting dates for the simulations using all available data obtained from different sources (government and private). Results indicate that the region is expected to have increased flows during the wet season and no significant changes during the dry season. Reservoir inflows are expected to increase up to 42 and 216% for the lowest and highest SSP evaluated, respectively. Similarly, the model projected streamflow increases up to 295 and 704%, respectively. Regarding yearly water availability and considering current and future demands for the watersheds under study, water deficits are not expected in the future if current reservoir storage can be maintained, though it is expected that reservoirs won’t be able to store predicted higher flows, so important volumes of water could be lost during the wet season to the ocean by natural drainage. Given the uncertainty of climate change projections, if future water sustainability is desired, storage and irrigation efficiencies should be improved and reservoir sedimentation should be evaluated.

Urban stormwater quality has been sampled and chemically analyzed in the city of Arequipa, southern Peru. Stormwater samples generated from a 0.04 km² drainage area in a downtown location were collected during two rainy seasons (2022 and 2023), including both first flush and peak flow for each storm event, analyzing physical and chemical (metals) variables. Results were compared with Peruvian agricultural irrigation standards, identifying also temporal changes and statistical correlations. Several metals (B, Cu, Fe, Mn, and Zn) were detected at concentrations above Peruvian MPLs, with B being the analyte that violated the norm more often. Most pollution occurred at the beginning of each rainy season and during the first flush stages. All vehicle-related contaminants were well correlated except for Pb and Se, which were assumed to have a different source of origin. We recommend that further investigations should focus on the effects of urban stormwater on downstream ecosystems in Peru. Similarly, we strongly recommend the creation of new regulations that ensure proper stormwater quality released from urban areas of this country, as well as preventive/treatment practices to minimize the pollution of downstream aquatic ecosystems and ensure healthy water to irrigate crops located downstream from cities.

This study focuses on the production and characterization of activated carbons derived from the carbonaceous residue obtained through the catalytic pyrolysis of waste tires. A catalytic pyrolysis process was conducted at 450 °C and 575 °C, employing two zeolitic catalysts, the commercial ZSM-5 and a synthesized zeolite (PZ2), developed from natural pozzolan, which played a key role in the pyrolysis performance and the quality of the resulting carbons. After pyrolysis, the solid residues were chemically activated using KOH to improve their porous structure and surface characteristics. Comprehensive characterization was carried out, including textural properties (BET surface area and porosity) and morphological (SEM) analysis of the activated carbons, as well as crystallinity evaluation (XRD) of the zeolitic catalysts. The BET surface areas of activated carbons PZ2-T1-AK and PZ2-T2-AK reached 608.65 m²/g and 624.37 m²/g, respectively, values that surpass those reported for similar materials under comparable activation conditions. The developed porous structure suggests strong potential for applications in adsorption processes, including pollutant removal. These findings demonstrate the effectiveness of zeolite-catalyzed pyrolysis, particularly using PZ2, as a sustainable strategy for transforming tire waste into high-performance adsorbent materials. This approach supports circular economy principles through innovative waste valorization and offers a promising solution to an environmental challenge.

The use of natural and synthetic zeolites as catalysts in the pyrolysis of used tires is a topic of increasing interest. This study reviews the importance of zeolites in this process, highlighting their role in improving the quality and quantity of the products obtained. The influence of factors such as the Si/Al ratio, thermal resistance, and pyrolysis process conditions on the efficiency of converting tires into oils, gases, and char is discussed. It is concluded that zeolites play a key role in the pyrolysis of tires, with different process variants and types of zeolites affecting the quality of the products obtained.